1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
implement Cfg;
include "sys.m";
include "bufio.m";
include "cfg.m";
sys : Sys;
bufio : Bufio;
Iobuf : import bufio;
ENOMOD : con "cannot load module";
EBADPATH : con "bad path";
init(path : string) : string
{
sys = load Sys Sys->PATH;
bufio = load Bufio Bufio->PATH;
if (bufio == nil)
return sys->sprint("%s: %r", ENOMOD);
iob := bufio->open(path, Sys->OREAD);
if (iob == nil)
return sys->sprint("%s: %r", EBADPATH);
# parse the config file
r : list of ref Tuple;
lnum := 0;
rlist : list of list of ref Tuple;
while ((line := iob.gets('\n')) != nil) {
lnum++;
(tuple, err) := parseline(line, lnum);
if (err != nil)
return sys->sprint("%s:%d: %s", path, lnum, err);
if (tuple == nil)
continue;
if (line[0] != ' ' && line[0] != '\t') {
# start of a new record
if (r != nil)
rlist = r :: rlist;
r = nil;
}
r = tuple :: r;
}
if (r != nil)
rlist = r :: rlist;
for (; rlist != nil; rlist = tl rlist)
insert(hd rlist);
return nil;
}
parseline(s : string, lnum : int) : (ref Tuple, string)
{
attrs : list of Attr;
quote := 0;
word := "";
lastword := "";
name := "";
loop:
for (i := 0 ; i < len s; i++) {
if (quote) {
if (s[i] == quote) {
if (i + 1 < len s && s[i+1] == quote) {
word[len word] = quote;
i++;
} else {
quote = 0;
continue;
}
} else
word[len word] = s[i];
continue;
}
case s[i] {
'\'' or '\"' =>
quote = s[i];
continue;
'#' =>
break loop;
' ' or '\t' or '\n' =>
if (word == nil)
continue;
if (lastword != nil) {
# lastword space word space
attrs = Attr(lastword, nil) :: attrs;
}
lastword = word;
word = nil;
if (name != nil) {
# name = lastword space
attrs = Attr(name, lastword) :: attrs;
name = lastword = nil;
}
'=' =>
if (lastword == nil) {
# word=
lastword = word;
word = nil;
}
if (word != nil) {
# lastword word=
attrs = Attr(lastword, nil) :: attrs;
lastword = word;
word = nil;
}
if (lastword == nil)
return (nil, "empty name");
name = lastword;
lastword = nil;
* =>
word[len word] = s[i];
}
}
if (quote)
return (nil, "missing quote");
if (lastword == nil) {
lastword = word;
word = nil;
}
if (name == nil) {
name = lastword;
lastword = nil;
}
if (name != nil)
attrs = Attr(name, lastword) :: attrs;
if (attrs == nil)
return (nil, nil);
fattrs : list of Attr;
for (; attrs != nil; attrs = tl attrs)
fattrs = hd attrs :: fattrs;
return (ref Tuple(lnum, fattrs), nil);
}
lookup(name : string) : list of (string, ref Record)
{
l := buckets[hash(name)];
for (; l != nil; l = tl l) {
hr := hd l;
if (hr.name != name)
continue;
return hr.vrecs;
}
return nil;
}
Record.lookup(r : self ref Record, name : string) : (string, ref Tuple)
{
for (ts := r.tuples; ts != nil; ts = tl ts) {
t := hd ts;
for (as := t.attrs; as != nil; as = tl as) {
a := hd as;
if (a.name == name)
return (a.value, t);
}
}
return (nil, nil);
}
Tuple.lookup(t : self ref Tuple, name : string) : string
{
for (as := t.attrs; as != nil; as = tl as) {
a := hd as;
if (a.name == name)
return a.value;
}
return nil;
}
reset()
{
keynames = nil;
buckets = array[HSIZE+1] of list of ref HRecord;
}
# Record hash table
HRecord : adt {
name : string;
vrecs : list of (string, ref Record);
};
keynames : list of string;
HSIZE : con 16rff; # must be (2^n)-1 due to hash() defn
buckets := array [HSIZE+1] of list of ref HRecord;
hash(name : string) : int
{
# maybe use hashPJW?
h := 0;
for (i := 0; i < len name; i++)
h = (h + name[i]) & HSIZE;
return h;
}
insert(rtups : list of ref Tuple) {
# tuple list is currently in reverse order
ftups : list of ref Tuple;
for (; rtups != nil; rtups = tl rtups)
ftups = hd rtups :: ftups;
maintuple := hd ftups;
mainattr := hd maintuple.attrs;
name := mainattr.name;
value := mainattr.value;
# does name already exist?
hr : ref HRecord;
h := hash(name);
l := buckets[h];
for (; l != nil; l = tl l) {
hr = hd l;
if (hr.name == name)
break;
}
if (l == nil) {
keynames = name :: keynames;
buckets[h] = ref HRecord(name, (value, ref Record(ftups))::nil) :: buckets[h];
} else
hr.vrecs = (value, ref Record(ftups)) :: hr.vrecs;
}
getkeys() : list of string
{
return keynames;
}
|
